[Intel-xe] [PATCH 1/4] drm/xe: Rework size helper to be a little more correct

Ruhl, Michael J michael.j.ruhl at intel.com
Wed May 3 14:14:22 UTC 2023


>-----Original Message-----
>From: Auld, Matthew <matthew.auld at intel.com>
>Sent: Wednesday, May 3, 2023 6:41 AM
>To: Ruhl, Michael J <michael.j.ruhl at intel.com>; intel-
>xe at lists.freedesktop.org
>Cc: Brost, Matthew <matthew.brost at intel.com>; Kershner, David
><david.kershner at intel.com>; Ghimiray, Himal Prasad
><himal.prasad.ghimiray at intel.com>; Upadhyay, Tejas
><tejas.upadhyay at intel.com>
>Subject: Re: [PATCH 1/4] drm/xe: Rework size helper to be a little more
>correct
>
>On 01/05/2023 12:58, Michael J. Ruhl wrote:
>> The _total_vram_size helper is device based and is not complete.
>>
>> Teach the helper to be tile aware and add the ability to size
>> DG1 correctly.
>>
>> Signed-off-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
>> ---
>>   drivers/gpu/drm/xe/regs/xe_gt_regs.h   |  2 +-
>>   drivers/gpu/drm/xe/xe_mmio.c           | 73 +++++++++++++++++---------
>>   drivers/gpu/drm/xe/xe_mmio.h           |  2 +-
>>   drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 28 +++++-----
>>   4 files changed, 64 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> index 68e89d71cd1c..780edd4dc1bd 100644
>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> @@ -74,7 +74,7 @@
>>   #define VE1_AUX_NV				XE_REG(0x42b8)
>>   #define   AUX_INV				REG_BIT(0)
>>
>> -#define XEHP_TILE0_ADDR_RANGE			XE_REG_MCR(0x4900)
>> +#define XEHP_TILE_ADDR_RANGE(_idx)		XE_REG_MCR(0x4900
>+ (_idx) * 4)
>>   #define XEHP_FLAT_CCS_BASE_ADDR
>	XE_REG_MCR(0x4910)
>>
>>   #define CHICKEN_RASTER_1			XE_REG_MCR(0x6204,
>XE_REG_OPTION_MASKED)
>> diff --git a/drivers/gpu/drm/xe/xe_mmio.c
>b/drivers/gpu/drm/xe/xe_mmio.c
>> index 3b719c774efa..7d53d382976c 100644
>> --- a/drivers/gpu/drm/xe/xe_mmio.c
>> +++ b/drivers/gpu/drm/xe/xe_mmio.c
>> @@ -148,34 +148,56 @@ static bool xe_pci_resource_valid(struct pci_dev
>*pdev, int bar)
>>   	return true;
>>   }
>>
>> -int xe_mmio_total_vram_size(struct xe_device *xe, u64 *vram_size, u64
>*usable_size)
>> +/**
>> + * xe_mmio_tile_vram_size - Collect vram size and off set information
>> + * @gt: tile to get info for
>> + * @vram_size: available vram (size - device reserved portions)
>> + * @tile_size: actual vram size
>> + * @tile_offset: physical start point in the vram address space
>> + *
>> + * There are 4 places for size information:
>> + * - io size (from pci_resource_len of LMEM bar) (only used for small bar
>and DG1)
>> + * - TILEx size (actual vram size)
>> + * - GSMBASE offset (TILEx - "stolen")
>> + * - CSSBASE offset (TILEx - CSS space necessary)
>> + *
>> + * NOTE: CSSBASE is always a lower/smaller offset then GSMBASE.
>> + *
>> + * The actual available size of memory is to the CCS or GSM base.
>> + * NOTE: multi-tile bases will include the tile offset.
>> + *
>> + */
>> +int xe_mmio_tile_vram_size(struct xe_gt *gt, u64 *vram_size, u64
>*tile_size, u64 *tile_offset)
>>   {
>> -	struct xe_gt *gt = xe_device_get_gt(xe, 0);
>> -	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>> +	u64 offset;
>>   	int err;
>>   	u32 reg;
>>
>> -	if (!xe->info.has_flat_ccs)  {
>> -		*vram_size = pci_resource_len(pdev, GEN12_LMEM_BAR);
>> -		if (usable_size)
>> -			*usable_size = min(*vram_size,
>> -					   xe_mmio_read64(gt,
>GSMBASE.reg));
>> -		return 0;
>> -	}
>> -
>>   	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>>   	if (err)
>>   		return err;
>>
>> -	reg = xe_gt_mcr_unicast_read_any(gt, XEHP_TILE0_ADDR_RANGE);
>> -	*vram_size = (u64)REG_FIELD_GET(GENMASK(14, 8), reg) * SZ_1G;
>> -	if (usable_size) {
>> +	/* actual size */
>> +	if (unlikely(gt->xe->info.platform == XE_DG1)) {
>> +		*tile_size = pci_resource_len(to_pci_dev(gt->xe->drm.dev),
>GEN12_LMEM_BAR);
>> +		*tile_offset = 0;
>> +	} else {
>> +		reg = xe_gt_mcr_unicast_read_any(gt,
>XEHP_TILE_ADDR_RANGE(gt->info.id));
>> +		*tile_size = (u64)REG_FIELD_GET(GENMASK(14, 8), reg) *
>SZ_1G;
>> +		*tile_offset = (u64)REG_FIELD_GET(GENMASK(7, 1), reg) *
>SZ_1G;
>> +	}
>> +
>> +	/* minus device usage */
>> +	if (gt->xe->info.has_flat_ccs) {
>>   		reg = xe_gt_mcr_unicast_read_any(gt,
>XEHP_FLAT_CCS_BASE_ADDR);
>> -		*usable_size = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) *
>SZ_64K;
>> -		drm_info(&xe->drm, "vram_size: 0x%llx usable_size:
>0x%llx\n",
>> -			 *vram_size, *usable_size);
>> +		offset = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) *
>SZ_64K;
>> +	} else {
>> +		offset = xe_mmio_read64(gt, GSMBASE.reg);
>>   	}
>>
>> +	/* remove the tile offset so we have just the available size */
>> +	*vram_size = offset - *tile_offset;
>> +
>>   	return xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
>>   }
>>
>> @@ -183,11 +205,12 @@ int xe_mmio_probe_vram(struct xe_device *xe)
>>   {
>>   	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>>   	struct xe_gt *gt;
>> -	u8 id;
>> -	u64 vram_size;
>>   	u64 original_size;
>> -	u64 usable_size;
>> +	u64 tile_offset;
>> +	u64 tile_size;
>> +	u64 vram_size;
>>   	int err;
>> +	u8 id;
>>
>>   	if (!IS_DGFX(xe)) {
>>   		xe->mem.vram.mapping = 0;
>> @@ -212,25 +235,25 @@ int xe_mmio_probe_vram(struct xe_device *xe)
>>   	gt = xe_device_get_gt(xe, 0);
>>   	original_size = pci_resource_len(pdev, GEN12_LMEM_BAR);
>>
>> -	err = xe_mmio_total_vram_size(xe, &vram_size, &usable_size);
>> +	err = xe_mmio_tile_vram_size(gt, &vram_size, &tile_size,
>&tile_offset);
>>   	if (err)
>>   		return err;
>>
>>   	xe_resize_vram_bar(xe, vram_size);
>>   	xe->mem.vram.io_start = pci_resource_start(pdev,
>GEN12_LMEM_BAR);
>> -	xe->mem.vram.io_size = min(usable_size,
>> +	xe->mem.vram.io_size = min(vram_size,
>>   				   pci_resource_len(pdev,
>GEN12_LMEM_BAR));
>>   	xe->mem.vram.size = xe->mem.vram.io_size;
>>
>>   	if (!xe->mem.vram.size)
>>   		return -EIO;
>>
>> -	if (usable_size > xe->mem.vram.io_size)
>> +	if (vram_size > xe->mem.vram.io_size)
>>   		drm_warn(&xe->drm, "Restricting VRAM size to PCI resource
>size (%lluMiB->%lluMiB)\n",
>> -			 (u64)usable_size >> 20, (u64)xe->mem.vram.io_size
>>> 20);
>> +			 (u64)vram_size >> 20, (u64)xe->mem.vram.io_size >>
>20);
>>
>>   	xe->mem.vram.mapping = ioremap_wc(xe->mem.vram.io_start, xe-
>>mem.vram.io_size);
>> -	xe->mem.vram.size = min_t(u64, xe->mem.vram.size, usable_size);
>> +	xe->mem.vram.size = min_t(u64, xe->mem.vram.size, vram_size);
>>
>>   	drm_info(&xe->drm, "TOTAL VRAM: %pa, %pa\n", &xe-
>>mem.vram.io_start, &xe->mem.vram.size);
>>
>> diff --git a/drivers/gpu/drm/xe/xe_mmio.h
>b/drivers/gpu/drm/xe/xe_mmio.h
>> index 1a32e0f52261..556cf3d9e4f5 100644
>> --- a/drivers/gpu/drm/xe/xe_mmio.h
>> +++ b/drivers/gpu/drm/xe/xe_mmio.h
>> @@ -120,6 +120,6 @@ static inline bool xe_mmio_in_range(const struct
>xe_mmio_range *range, u32 reg)
>>   }
>>
>>   int xe_mmio_probe_vram(struct xe_device *xe);
>> -int xe_mmio_total_vram_size(struct xe_device *xe, u64 *vram_size, u64
>*flat_ccs_base);
>> +int xe_mmio_tile_vram_size(struct xe_gt *gt, u64 *vram_size, u64
>*tile_size, u64 *tile_base);
>>
>>   #endif
>> diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> index 9ce0a0585539..a329f12f14fe 100644
>> --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> @@ -51,27 +51,27 @@ bool xe_ttm_stolen_cpu_access_needs_ggtt(struct
>xe_device *xe)
>>   	return GRAPHICS_VERx100(xe) < 1270 && !IS_DGFX(xe);
>>   }
>>
>> -static s64 detect_bar2_dgfx(struct xe_device *xe, struct
>xe_ttm_stolen_mgr *mgr)
>> +static s64 detect_bar2_dgfx(struct xe_gt *gt, struct xe_ttm_stolen_mgr
>*mgr)
>>   {
>> -	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>> -	struct xe_gt *gt = to_gt(xe);
>> -	u64 vram_size, stolen_size;
>> -	int err;
>> +	u64 stolen_size;
>> +	u64 tile_offset;
>> +	u64 tile_size;
>> +	u64 vram_size;
>>
>> -	err = xe_mmio_total_vram_size(xe, &vram_size, NULL);
>> -	if (err) {
>> -		drm_info(&xe->drm, "Querying total vram size failed\n");
>> +	if (xe_mmio_tile_vram_size(gt, &vram_size, &tile_size, &tile_offset))
>{
>> +		drm_info(&gt->xe->drm, "Querying total vram size failed\n");
>>   		return 0;
>>   	}
>>
>>   	/* Use DSM base address instead for stolen memory */
>> -	mgr->stolen_base = xe_mmio_read64(gt, DSMBASE.reg) &
>BDSM_MASK;
>> -	if (drm_WARN_ON(&xe->drm, vram_size < mgr->stolen_base))
>> +	mgr->stolen_base = (xe_mmio_read64(gt, DSMBASE.reg) &
>BDSM_MASK) - tile_offset;
>> +	if (drm_WARN_ON(&gt->xe->drm, tile_size < mgr->stolen_base))
>>   		return 0;
>>
>> -	stolen_size = vram_size - mgr->stolen_base;
>> -	if (mgr->stolen_base + stolen_size <= pci_resource_len(pdev, 2))
>> -		mgr->io_base = pci_resource_start(pdev, 2) + mgr-
>>stolen_base;
>> +	stolen_size = tile_size - mgr->stolen_base;
>> +
>> +	if (mgr->stolen_base + stolen_size <= tile_size)
>
>I think needs to be the pci_len() here.

For a PVC that would be 128GB for length.  That will encompass both tiles, and I think that the
this will not check correctly.

tile_size == pci_len() for DG1...

Is that your concern?

I think that he "stolen" area has to be constrained to the tile size, not the complete area.
Am I missing something here?

Thanks

Mike

>> +		mgr->io_base = gt->mem.vram.io_start + mgr->stolen_base;
>>
>>   	/*
>>   	 * There may be few KB of platform dependent reserved memory at
>the end
>> @@ -139,7 +139,7 @@ void xe_ttm_stolen_mgr_init(struct xe_device *xe)
>>   	int err;
>>
>>   	if (IS_DGFX(xe))
>> -		stolen_size = detect_bar2_dgfx(xe, mgr);
>> +		stolen_size = detect_bar2_dgfx(to_gt(xe), mgr);
>>   	else if (GRAPHICS_VERx100(xe) >= 1270)
>>   		stolen_size = detect_bar2_integrated(xe, mgr);
>>   	else


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